mrclark303 wrote: ↑29 Mar 2023, 16:21
NickC wrote: ↑29 Mar 2023, 14:32
Little J wrote: ↑29 Mar 2023, 08:20
That prompts an interesting question, if you put the M157 optic on legacy rifles how much of an advantage does the M7 still have? Yes it's going to be a wide margin over a short barreled 556, but what about 762 (or 6.5 CM)? Would it still be worth investing in a new platform?
Why would you buy an expensive M157 FCS/optic, it might be costing more than the M7 rifle? presume could fit on say the legacy 7.62 L129A1 rifle. For a 5.56x45 ~400 m range assault rifle, would not a relatively cheap fixed three power wide angle scope be cheaper and more suitable.
Interesting thing about 5.56mm, it's a great calibre in regards the volume of ammunition an individual can carry and within its range limitations, but it's sadly lacking in range ballistic performance.
It's a simple matter of physics, it's a very small light bullet, so it lacks the mass and kinetic energy to retain accuracy over 400 yards, 300 plus starts to get iffy if you have a strong cross wind.
It rapidly bleeds energy and individual rounds will deflect in utterly random and rapidly changing directions with a strong wind.
I remember having this shown to me with 5.56 tracer in extremely blustery conditions, it really has to be seen to be believed.
7.62mm will shoot (minute of man) out to 700 yards and further in the same conditions... Not laser accurate, but plenty good enough for government work....
.338, well, it's an express train of a round, thundering down range with enough energy and mass to drill through wind sheer, and very little will stop it finding its mark out to extended ranges...
As far as know the only full-on post WWII detailed statistical analysis operational research report pp105 into the effectiveness of rifle fire was carried out by the John Hopkins University for the US Army.
"CONCLUSIONS
1. The ranges at which the rifle is used most frequently in battle and the ranges within which
the greater fraction of man targets can be seen on the battlefield do not exceed 300 yd.
2.
Within these important battle ranges, the marksmanship of even expert riflemen is satisfactory in meeting actual battle requirements only up to 100 yd, beyond 100 yd marksmanship declines sharply, reaching a low order at 300 yd.
3. To improve hit effectiveness at the ranges not covered satisfactorily in this sense by men using the M - 1 (100 to 300 yd), the adoption of a pattern-dispersion principle in the hand weapon could partly compensate for human aiming errors and thereby significantly increase the hits at ranges up to 300 yd.
4 . Current models of fully automatic hand weapons afford neither these desirable characteristics nor adequate alternatives. Such weapons are valueless from the standpoint of increasing the number of targets hit when aiming on separated man-size targets.
5. Certain of the costly high standards of accuracy observed in the manufacture of current rifles and ammunition can be relaxed without significant losses in over-all hit effectiveness.
6 . To meet the actual operational requirements of a general purpose infantry hand weapon many possibilities are open for designs which will give desirable dispersion patterns (and accompanying increases in hit probability) at the ranges of interest. Of the .possible salvo or volley automatic designs, the small caliber, lightweight weapon with controlled dispersion characteristics appears to be a promi sing approach. (Low recoil of a small caliber weapon facilitates dispersion control.)
7. To create militarily acceptable wound damage at common battle ranges, missiles of smaller caliber than the present standard .30 caliber can be used without loss in wounding effects and with substantial logistical and over-all military gains.
8. A very great increase in hit lethality can be effected by the addition of toxic agents to bullet missiles."
RECOMMENDATIONS
1. It is recommended that the Ordnance Corps proceed to determine the design or technological feasibility of developing a hand weapon which has the characteristics cited in this analysis, namely:
a.
Maximum hit effectiveness against man targets within 300 yd range. (This does not mean that 'the weapon will be ineffective beyond this range.)
b.
Small caliber (less than . 30).
c. Wounding capability up to 300 yd at least equivalent to the present rifle.
d.
Dispersion of rounds from salvos or bursts controlled so as to form a pattern such that aiming errors up to 300 yd will be partly compensated, and hit effectiveness thereby increased for these ranges.
2. As one possible alternative to the current "volume of fire 11 (fully automatic) approach to the problem of increasing the effective firepower of infantry riflemen, it is recommended-subject to tentative confirmation of design feasibility-that a rifle incorporating at least in principle the military characteristics here proposed be manufactured for further and conclusive test. "
Think the conclusions have stood the test of time very well. Its not a "simple matter of physics and sadly lacking in range ballistic performance", the report makes it clear that's not a priority but "Dispersion of rounds from salvos or bursts controlled so as to form a pattern such that aiming errors up to 300 yd will be partly compensated, and hit effectiveness thereby increased for these ranges." the report conclusions appears to mirror the Wehrmacht Grenadier assault platoons use of the StG 45 with the 7.92x33 on the Eastern front though severely limited in numbers of rifles or ammo.
Do agree the 5.56x45 not the best choice but as said its a fait accompli and with the great advantage of light weight allowing high volume of fire.
https://apps.dtic.mil/sti/citations/AD0000346